A new Ga(III) complex with imidazole (IMZ) in 1:2 Ga:IMZ stoichiometric ratio has been synthesised. The complex has been characterised by spectroscopic (IR, NMR, UV-Vis.,), thermogravimetric (TG, DTG, DTA), electrophoresis and microanalytical techniques and shown to be [GaCl(IMZ)2(H2O)]. The geometry of [GaCl(IMZ)2(H2O)]was optimised in a singlet state by the DFT method with B3LYP functional. Theoretical analysis of vibration modes of this complex has been undertaken and the results were compared with the experimental data for this compound. The complex was subjected to radiolabelling with 67Ga via the nuclear reaction 68Zn (p, 2n) 67Ga. The radiochemical yield was greater than 80%. HPLC analysis in isotonic systems revealed that this complex is highly unstable in an isotonic system where it readily dissociated. The investigated complex showed relatively high anti-bacterial activities compared with the freeligand